DETERMINATION OF NANOMETER-SCALE SIZES IN n+-TYPE POROUS SILICON BY THE USE OF X-RAY AND RAMAN SPECTROSCOPIES

2002 ◽  
Vol 09 (05n06) ◽  
pp. 1769-1772
Author(s):  
A. RAMÍREZ-PORRAS

Porous silicon layers were obtained by electrochemical etching on (111) plane surfaces of crystalline phosphorus-doped silicon in the presence of hydrofluoric acid. The photoluminescence of this kind of layers when illuminated with UV light is possibly explained by the quantum confinement model (QCM), which states the presence of nanometer-scale crystallites that enlarge the semiconductor band gap up to optical photon energies when the band-to-band recombination processes take place. In this study, the size determination of those proposed structures was performed by X-ray diffractiometry and by Raman spectroscopy. The obtained results suggest a consistency between the experimental work and the QCM.

1991 ◽  
Vol 256 ◽  
Author(s):  
David L. Naylor ◽  
Sung B. Lee ◽  
John C. Pincenti ◽  
Brett E. Bouma

ABSTRACTPhotoluminescence spectra have been measured in porous silicon following electrochemical etching in dilute hydrofluoric acid (HF). The effects of HF concentration during etching on the efficiency and peak wavelength of photoluminescence have been investigated. The effects of temperature between 25°C and 200°C on PL spectra have been recorded. Photoluminescence lifetimes as a function of wavelength have been studied following ultrashort UV photoexcitation. A number of lifetime components in the decay are observed the longest in good agreement over the wavelength range of 500 to 600 nm with a silicon quantum wire model. At longer wavelengths a departure from lifetimes of the wire model is observed and two hypotheses for the discrepancy are presented.


1992 ◽  
Vol 283 ◽  
Author(s):  
R. Tsu ◽  
L. Ioriatti ◽  
J. F. Harvey ◽  
H. Shen ◽  
R. A. Lux

ABSTRACTThe reduction of the dielectric constant due to quantum confinement is studied both experimentally and theoretically. Angle resolved ellipsometry measurements with Ar- and He-Ne-lasers give values for the index of refraction far below what can be accounted for from porosity alone. A modified Penn model to include quantum size effects has been used to calculate the reduction in the static dielectric constant (ε) with extreme confinement. Since the binding energy of shallow impurities depends inversely on ε2, the drastic decrease in the carrier concentration as a result of the decrease in ε leads to a self-limiting process for the electrochemical etching of porous silicon.


2018 ◽  
Vol 7 (3.11) ◽  
pp. 48
Author(s):  
Kevin Alvin Eswar ◽  
Mohd Husairi Fadzillah Suhaimi ◽  
Muliyadi Guliling ◽  
Zuraida Khusaimi ◽  
Mohamad Rusop ◽  
...  

ZnO Nanostructures have been successfully deposited on of Porous silicon (PSi) via wet colloid chemical approach. PSi was prepared by electrochemical etching method. ZnO/PSi thin films were annealed in different temperature in the range of 300 °C to 700 °C. Surface morphology studies were conducted using field emission scanning microscopy (FESEM). Flower-like structures of ZnO were clearly seen at annealing temperature of 500 °C. The X-ray diffraction spectra (XRD) have been used to investigate the structural properties. There are three dominant peaks referred to plane (100), (002) and (101) indicates that ZnO has a polycrystalline hexagonal wurtzite structures. Plane (002) shows the highest intensities at annealing temperature of 500 °C. Based on plane (002) analysis, the sizes were in range of 30.78 nm to 55.18. In addition, it was found that the texture coefficient of plane (002) is stable compared to plane (100) and (101). 


Author(s):  
Alexander S. Lenshin ◽  
Anatoly N. Lukin ◽  
Yaroslav A. Peshkov ◽  
Sergey V. Kannykin ◽  
Boris L. Agapov ◽  
...  

The aim of this work was the formation of multilayer structures of macroporous silicon and the study of their structural, morphological, and optical properties in comparison with the properties of multilayer structures of mesoporous silicon. The paper presents the results of the development of techniques for the formation of multilayer structures of porous silicon por-Si by stepwise change in the current with two-stage modes of electrochemical etching.The data on the morphology, composition, and porosity of macroporous and mesoporous silicon samples were obtained using scanning electron microscopy, IR spectroscopy, and X-ray reflectivity. It was shown that with the two-stage growth of porous silicon layers, the depth of the boundary between the layers of the structure was determined by the primary mode of electrochemical etching, while the total layer thickness increased with an increase in the current density of electrochemical etching.A comparative analysis of the relative intensity and fine structure of vibrational modes of IR spectra indicated a significantly more developed specific pore surface and greater sorption capacity of mesoporous silicon as compared to macroporous silicon.     REFERENCES 1. Pacholski C. Photonic crystal sensors based on porous silicon. Sensors. 2013;13(4): 4694–4713. https://doi.org/10.3390/s130404694 2. Harraz F. A. Porous silicon chemical sensors and biosensors: A review. Sensors and Actuators B: Chemical. 2014;202: 897–912. https://doi.org/10.1016/j.snb.2014.06.0483. Qian M., Bao X. Q., Wang L. W., Lu X., Shao J., Chen X. S. Structural tailoring of multilayer porous silicon for photonic crystal application. Journal of Crystal Growth. 2006;292(2): 347–350. https://doi.org/10.1016/j.jcrysgro.2006.04.0334. Len’shin A. S., Kashkarov V. M., Turishchev S. Yu., Smirnov M. S., Domashevskaya E. P. Effect of natural aging on photoluminescence of porous silicon. Technical Physics Letters. 2011;37(9): 789–792. https://doi.org/10.1134/S10637850110901245. Kheifets L. I., Neimark A. B. Multiphase processes in porous media. Moscow: Khimiya Publ.; 1982. 320 p. (In Russ.)6. Canham L. Handbook of porous silicon. Switzerland: Springer International Publishing; 2014. 733 p.7. Zimin S. P. Porous silicon – material with new properties. Soros Educational Journal. 2004;8(1): 101–107. Available at: http://window.edu.ru/resource/217/21217/files/0401_101.pdf (In Russ., abstract in Eng.) 8. Seredin P. V., Lenshin A. S., Goloshchapov D. L., Lukin A. N., Arsentyev I. N., Bondarev A. D., Tarasov I. S. Investigations of nanodimensional Al2O3films deposited by ion-plasma sputtering onto porous silicon. Semiconductors. 2015;49(7): 915–920. https://doi.org/10.1134/S10637826150702109. Seredin P. V., Lenshin A. S., Mizerov A. M., Leiste H., Rinke M. Structural, optical and morphological properties of hybrid heterostructures on the basis of GaN grown on compliant substrate por-Si(111). Applied Surface Science. 2019;476: 1049–1060. https://doi.org/10.1016/j.apsusc.2019.01.23910. Seredin P. V., Leiste H., Lenshin A. S., Mizerov A. M. Effect of the transition porous silicon layer on the properties of hybrid GaN/SiC/por-Si/Si(111) heterostructures. Applied Surface Science. 2020;508(145267): 1–14. https://doi.org/10.1016/j.apsusc.2020.14526711. Lenshin A. S., Barkov K. A., Skopintseva N. G., Agapov B. L., Domashevskaya E. P. Influence of electrochemical etching modes under one stage and two Stage formation of porous silicon on the degree of oxidation of its surface layer under natural conditions. Kondensirovannye sredy i mezhfaznye granitsy = Condensed Matter and Interphases. 2019;21(4): 534–543. https://doi.org/10.17308/kcmf.2019.21/2364 (In Russ., abstract in Eng.) 12. Buttard D., Dolino G., Bellet D., Baumbach T., Rieutord F. X-ray reflectivity investigation of thin p-type porous silicon layers. Solid State Communications. 1998;109(1): 1–5. https://doi.org/10.1016/S0038-1098(98)00531-613. Lenshin A. S., Seredin P. V., Agapov B. L., Minakov D. A., Kashkarov V. M. Preparation and degradation of the optical properties of nano-, meso‑,and macroporous silicon. Materials Science in Semiconductor Processing. 2015;30: 25–30. https://doi.org/10.1016/j.mssp.2014.09.04014. Ksenofontova O. I., Vasin A. V., Egorov V. V., Bobyl’ A. V., Soldatenkov F. Yu., Terukov E. I., Ulin V. P., Ulin N. V., Kiselev O. I. Porous silicon and its applications in biology and medicine. Technical Physics. 2014;59(1): 66–77. https://doi.org/10.1134/S1063784214010083


2019 ◽  
pp. 89
Author(s):  
S.M. Manakov ◽  
M.K. Ibraimov ◽  
Ye. Sagidolda ◽  
Sh.A. Zhumatova ◽  
M.B. Darmenkulova

In this work porous silicon samples obtained by electrochemical etching were investigated. Using scanning probe microscope the morphology of porous silicon samples was studied. To determine the thickness of the porous layer and the pore diameter, micrographs were obtained using a scanning electron microscope. The dimensions of the nanocrystallites were determined from the Raman spectra. For the detection of vapors of organic compounds, planar structures were used. The results of the study confirmed the possibility of using nanoporous silicon as a sensitive material for the determination of acetonitrile and chloroform vapors. It is shown that the adsorption phenomena in porous silicon depend on its structure and morphology. It is established that the humidity of the air when detecting the vapors of organic compounds under investigation has a significant effect on the sensitivity. It is also shown that such structures can be used as instruments for measuring air humidity.


2005 ◽  
Vol 87 (21) ◽  
pp. 211906 ◽  
Author(s):  
R. J. Martín-Palma ◽  
L. Pascual ◽  
P. Herrero ◽  
J. M. Martínez-Duart

1996 ◽  
Vol 97 (7) ◽  
pp. 549-552 ◽  
Author(s):  
S Eisebitt ◽  
J Lüning ◽  
J.-E Rubensson ◽  
T van Buuren ◽  
S.N Patitsas ◽  
...  

1994 ◽  
Vol 332 ◽  
Author(s):  
H.Z. Song ◽  
L.Z. Zhang ◽  
B.R. Zhang ◽  
G.G. Qin

ABSTRACTIt was found that porous silicon (PS) layers formed on 0.01 Ωcm (111) and 0.02 Ωcm (100) Si substrates show high photoluminescence (PL) peak energies on both lower and higher porosity sides and a minimum of PL peak energy at the moderate porosity, while those formed on 0.8 and 10Ωcm (111) p-type Si substrates show an increase of PL peak energy with porosity on the lower side and a saturation of PL peak energy with porosity on the higher side. These experimental facts are not consistent with the quantum confinement model for light emission of PS, which predicts a monotonous increase of PL peak energy with PS porosity.


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